<template>
  <div
    class="xtx-carousel"
    @mouseenter="handlePausePlay"
    @mouseleave="handleAutoPlay"
  >
    <ul class="carousel-body">
      <li
        class="carousel-item"
        v-for="(item, index) in sliders"
        :key="item.id"
        :class="{ fade: currentIndex === index }"
      >
        <RouterLink v-if="item.hrefUrl" :to="item.hrefUrl">
          <img v-src="item.imgUrl" alt="" />
        </RouterLink>
        <div v-else class="slider">
          <RouterLink
            v-for="goods in item"
            :key="goods.id"
            :to="`/product/${goods.id}`"
          >
            <img v-src="goods.picture" alt="" />
            <p class="name ellipsis">{{ goods.name }}</p>
            <p class="price">&yen;{{ goods.price }}</p>
          </RouterLink>
        </div>
      </li>
    </ul>
    <a href="javascript:;" class="carousel-btn prev" @click="handleToggle(-1)">
      <i class="iconfont icon-angle-left"></i>
    </a>
    <a href="javascript:;" class="carousel-btn next" @click="handleToggle(1)">
      <i class="iconfont icon-angle-right"></i>
    </a>
    <div class="carousel-indicator">
      <span
        v-for="(i, index) in sliders"
        :key="i.id"
        :class="{ active: currentIndex === index }"
        @click="currentIndex = index"
      ></span>
    </div>
  </div>
</template>

<script>
import { onUnmounted, ref, watch } from 'vue'
export default {
  name: 'XtxCarousel',
  props: {
    sliders: {
      type: Array,
      default: () => []
    },
    duration: {
      type: Number,
      default: 3000
    },
    autoPlay: {
      type: Boolean,
      default: true
    }
  },
  setup (props) {
    // 轮播图下标
    const currentIndex = ref(0)

    // 手动轮播
    const handleToggle = step => {
      const { length } = props.sliders // 边界长度
      const temp = currentIndex.value + step // 临时变量
      // 边界限定
      if (temp <= -1) return (currentIndex.value = length - 1)
      if (temp >= length) return (currentIndex.value = 0)
      currentIndex.value = temp
    }

    let timerId = null

    // 关闭轮播
    const handlePausePlay = () => clearInterval(timerId)

    // 自动轮播
    const handleAutoPlay = () => {
      const { duration, autoPlay } = props
      if (!autoPlay) return
      handlePausePlay()
      timerId = setInterval(() => handleToggle(1), duration)
    }

    // 监听 - 轮播图至少为 2 才自动播放
    watch(
      () => props.sliders,
      ({ length }) => {
        if (length > 1) handleAutoPlay()
      },
      { immediate: true }
    )

    // 组件卸载 - 关闭轮播
    onUnmounted(() => handlePausePlay())

    return { currentIndex, handleToggle, handleAutoPlay, handlePausePlay }
  }
}
</script>

<style scoped lang="less">
// 轮播商品
.slider {
  display: flex;
  justify-content: space-around;
  padding: 0 40px;
  > a {
    width: 240px;
    text-align: center;
    img {
      padding: 20px;
      width: 230px !important;
      height: 230px !important;
    }
    .name {
      font-size: 16px;
      color: #666;
      padding: 0 40px;
    }
    .price {
      font-size: 16px;
      color: @priceColor;
      margin-top: 15px;
    }
  }
}
.xtx-carousel {
  width: 100%;
  height: 100%;
  min-width: 300px;
  min-height: 150px;
  position: relative;
  .carousel {
    &-body {
      width: 100%;
      height: 100%;
    }
    &-item {
      width: 100%;
      height: 100%;
      position: absolute;
      left: 0;
      top: 0;
      opacity: 0;
      transition: opacity 0.5s linear;
      &.fade {
        opacity: 1;
        z-index: 1;
      }
      img {
        width: 100%;
        height: 100%;
      }
    }
    &-indicator {
      position: absolute;
      left: 0;
      bottom: 20px;
      z-index: 2;
      width: 100%;
      text-align: center;
      span {
        display: inline-block;
        width: 12px;
        height: 12px;
        background: rgba(0, 0, 0, 0.2);
        border-radius: 50%;
        cursor: pointer;
        ~ span {
          margin-left: 12px;
        }
        &.active {
          background: #fff;
        }
      }
    }
    &-btn {
      width: 44px;
      height: 44px;
      background: rgba(0, 0, 0, 0.2);
      color: #fff;
      border-radius: 50%;
      position: absolute;
      top: 228px;
      z-index: 2;
      text-align: center;
      line-height: 44px;
      opacity: 0;
      transition: all 0.5s;
      &.prev {
        left: 20px;
      }
      &.next {
        right: 20px;
      }
    }
  }
  &:hover {
    .carousel-btn {
      opacity: 1;
    }
  }
}
</style>
